Clinicopathological profile of colorectal cancer managed at a university teaching hospital, Nepal

Introductions: Colorectal carcinoma is the third most common cancer worldwide. The incidence is increasing in developing countries including Nepal. The aim of this study is to find out the clinicopathological pattern of colorectal carcinoma locally.  Methods: Data were recorded retrospectively by reviewing the charts of the patients who were diagnosed and treated for in patients having colorectal cancer managed during three years period of 2016-9 at Patan Hospital, the university teaching hospital of Patan Academy of health sciences, Nepal. Clinicopathological profile, age, gender, surgery, histopathological findings were descriptively analised. Results:  There were 36 colorectal cancer patients, male 20 (56%) and females 16 (44%), mean age 56.9 years (range 24 to 89). Curative surgery was possible in 17 (47.2%) and adenocarcinoma of moderate differentiation was found in 25 (70%) of the resected specimen. Conclusions: Colorectal carcinoma was found in old age, slightly more in male than female, adenocarcinoma being most common histology type.  Keywords: adenocarcinoma, colorectal carcinoma (CRC), curative resectio

Outcome of gastrointestinal surgery during COVID-19 lockdown in a tertiary care hospital, Nepal

Introduction: Perioperative strategies have been changing due to the COVID-19 pandemic to prevent the risk of postoperative complications and transmission of infection. This study was aimed to assess the outcome of gastrointestinal surgery and the risk of transmission by implementing COVID-19 testing criteria and surgical strategy. Method: This was a retrospective descriptive study conducted at the department of surgery at Patan Hospital, Nepal, during COVID-19 lock-down from 24 march to 15 June 2020. All patients who underwent gastrointestinal (GI) surgery were included. High-risk patients (as defined by the Hospital Incident Command System, HICS) were tested for COVID-19 preoperatively. Surgery was performed in COVID operating room with full protective gear. Low-risk patients were not tested for COVID-19 preoperatively and performed surgery in non-COVID OR. Data from patient’s case-sheets were analyzed descriptively for age, gender, comorbidities, hospital stay, RT-PCR results, surgeries, and postoperative complications. Result: There were total 44 GI surgeries performed; 31(70.5%) were emergency, 5(11.3%) semi-emergency and 8(18.2%) oncology. There were 11(25%) patients tested for COVID-19 preoperatively and were negative. Nine HCWs tested for COVID-19 randomly were negative. Severe postoperative complications developed in 3 patients, with one mortality. Conclusion: Among GI surgeries, there was no increase in postoperative complications and transmission of COVID-19 to the patients or HCWs following the implementation of standard testing criteria and surgical strategy

Ni-Catalyzed Regioselective Dicarbofunctionalization of Unactivated Olefins by Tandem Cyclization/Cross-Coupling and Application to the Concise Synthesis of Lignan Natural Products

We disclose a (terpy)­NiBr₂-catalyzed reaction protocol that regioselectively difunctionalizes unactivated olefins with tethered alkyl halides and arylzinc reagents. The reaction shows an excellent functional group tolerance (such as ketones, esters, nitriles, and halides) and a moderate to good level of diastereoselectivity. The current cyclization/cross-coupling also tolerates molecules containing base-sensitive racemizable stereocenters, which are preserved without racemization during the reaction. This cyclization/cross-coupling provides a rapid access to (arylmethyl)­carbo- and heterocyclic scaffolds, which occur widely as structural cores in various natural products and bioactive molecules. In order to show synthetic utility and generality, we have applied this new method in gram-scale quantities to the concise synthesis of six lignan natural products containing three different structural frameworks. We further conducted mechanistic investigations with radical probes and selectivity studies, which indicated that the current reaction proceeds via a single electron transfer (SET) process

Ni-Catalyzed Regioselective β,δ-Diarylation of Unactivated Olefins in Ketimines via Ligand-Enabled Contraction of Transient Nickellacycles: Rapid Access to Remotely Diarylated Ketones

We disclose a [(PhO)₃P]/NiBr₂-catalyzed regioselective β,δ-diarylation of unactivated olefins in ketimines with aryl halides and arylzinc reagents. This diarylation proceeds at remote locations to the carbonyl group to afford, after simple H⁺ workup, diversely substituted β,δ-diarylketones that are otherwise difficult to access readily with existing methods. Deuterium-labeling and crossover experiments indicate that diarylation proceeds by ligand-enabled contraction of transient nickellacycles

Ni-Catalyzed Regioselective β,δ-Diarylation of Unactivated Olefins in Ketimines via Ligand-Enabled Contraction of Transient Nickellacycles: Rapid Access to Remotely Diarylated Ketones

We disclose a [(PhO)₃P]/NiBr₂-catalyzed regioselective β,δ-diarylation of unactivated olefins in ketimines with aryl halides and arylzinc reagents. This diarylation proceeds at remote locations to the carbonyl group to afford, after simple H⁺ workup, diversely substituted β,δ-diarylketones that are otherwise difficult to access readily with existing methods. Deuterium-labeling and crossover experiments indicate that diarylation proceeds by ligand-enabled contraction of transient nickellacycles

Ni-Catalyzed Regioselective 1,2-Dicarbofunctionalization of Olefins by Intercepting Heck Intermediates as Imine-Stabilized Transient Metallacycles

We disclose a strategy for Ni-catalyzed dicarbofunctionalization of olefins in styrenes by intercepting Heck C­(sp³)–NiX intermediates with arylzinc reagents. This approach utilizes a readily removable imine as a coordinating group that plays a dual role of intercepting oxidative addition species derived from aryl halides and triflates to promote Heck carbometalation and stabilizing the Heck C­(sp³)–NiX intermediates as transient metallacycles to suppress β-hydride elimination and facilitate transmetalation/reductive elimination steps. This method affords diversely substituted 1,1,2-triarylethyl products that occur as structural motifs in various natural products

Ni-Catalyzed Regioselective Alkylarylation of Vinylarenes via C(sp³)–C(sp³)/C(sp³)–C(sp²) Bond Formation and Mechanistic Studies

We report a Ni-catalyzed regioselective alkylarylation of vinylarenes with alkyl halides and arylzinc reagents to generate 1,1-diarylalkanes. The reaction proceeds well with primary, secondary and tertiary alkyl halides, and electronically diverse arylzinc reagents. Mechanistic investigations by radical probes, competition studies and quantitative kinetics reveal that the current reaction proceeds via a Ni(0)/Ni­(I)/Ni­(II) catalytic cycle by a rate-limiting direct halogen atom abstraction via single electron transfer to alkyl halides by a Ni(0)-catalyst